FIG. 1 shows at 10 a sub-surface pump of the type commonly used in the prior art. The sub-surface pump 10, which is shown in FIG. 1, is of a type manufactured by Harbison-Fischer, of Crowley, Tex., which is utilized for the pumping of oil from an oil well. The pump 10 includes a valve rod 12 which is connected, at one end, to the sucker rod of the oil well. The valve rod 12 extends into the downhole tubing 14. In particular, the valve rod 12 is received within the working barrel 16 of the pump apparatus 10. The valve rod 12 is connected to the plunger 18 through the plunger cage 20. A one way valve 22 is provided at an end of the plunger 18 opposite the plunger cage 20. Another one way valve 24 is provided at the end of the working barrel 16 below the one way valve 22 of the plunger 18.
In normal operation, the sucker rod associated with the oil well will cause the valve rod 12 to move upwardly and downwardly. As the valve rod 12 moves downwardly, the one way valve 22 will open so as to allow oil and any suspended sand to enter the interior of the plunger 18. When the plunger 18 reaches the bottom of its stroke, the one way valve 22 will close so as to retain the oil and suspended sand within the interior of the plunger 18. The oil and suspended sand will exit the plunger 18 so as to be delivered into the interior of the tubing 14 for transport to the surface. Unfortunately, when oil is released from the plunger 18, the sand will tend to settle in the area around the top of the plunger 18. Eventually, this sand will wear on the plunger and its associated sealing mechanisms. This grinding action caused by the sand will cause the seal to wear down and lose pressure. Ultimately, it could cause the seizure of the pump. The sand will tend to accumulate in the small cavity on the top of the plunger 18 between the working barrel 16 and the plunger cage 20. When the plunger 18 moves upwardly, the one way valve 24 will open so as to allow oil and suspended sand to enter the interior 26 of the working barrel 16.
Referring to FIG. 2, a more detailed view of the pump 10 is illustrated. In particular, it can be seen that the plunger cage 20 is positioned within the working barrel 16 of the pump apparatus. The upper threaded end 17 of the plunger 18 is threadedly received by the interior threads 19 of the plunger cage 20. As can be seen in FIG. 2, sand can accumulate on the top of the plunger 18. On the upstroke of the plunger cage 20, the sand is forced between the plunger 18 and the wall of the working barrel 16.
FIG. 2 also shows the lower part of the plunger 18. As can be seen, the ball valve 22 is threadedly received by the exterior threads 21 at the bottom of the plunger 18. In particular, the upper portion of the ball valve 22 has an internally threaded section 25 which threadedly attaches to the exterior threads 21 of the plunger 18. A seat plug 27 is threadedly affixed to the bottom of the ball valve 22. Seat plug 27 has an interior passageway 29 which allows oil to flow therethrough toward the ball valve 22. As can be seen in FIG. 2, sand is shown as trapped between the traveling valve cage 20 and the working barrel 16. On the downstroke, the sand is forced between the plunger 18 and the working barrel 16.
It is an object of the present invention to provide a device for use on the plunger so as to effectively keep sand from accumulating in sensitive locations around the plunger.
It is another object of the present invention to provide a device which effectively flushes sand from critical areas of the pumping apparatus.
It is still another object of the present invention to provide a sand removal device which extends the life of the pumping mechanism and reduces the deteriorating effects caused by sand accumulation.
It is still a further object of the present invention to provide a device for the removal of sand which is easy to use, easy to install, and relatively inexpensive.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.